BACKGROUND We hypothesized that increased myocardial oxygen demand resulting from hypotension and reflex tachycardia unmasking a reduced endocardial myocardial blood flow (MBF) reserve is the mechanism of dipyridamole-induced regional dysfunction in chronic coronary artery disease. METHODS AND RESULTS Ameroid constrictors were placed around the proximal coronary arteries and their major branc...

Objective: The aim of this study is to evaluate the efficacy of dipyridamole in relieving the vasospasm of coronary artery bypass grafts. Material and Methods: Twenty two patients who underwent elective coronary artery bypass grafting (CABG) were admitted to the study (Men/Women:14/8, mean age: 62.4±8.8 years). Ten samples from left internal mammary(LIMA), radial arterial (RA) and saphenous vei...

We have carried out a clinical trial in 23 patients to determine whether dipyridamole modulates the clinical effect of methotrexate. This trial was based upon in vitro studies which indicate that dipyridamole potentiates the cytotoxic action of methotrexate through inhibition of thymidine salvage. Methotrexate was given as a bolus injection 24 h after initiation of a high dose dipyridamole infu...

The pressor response to exercise is of great importance in both physiology and pathophysiology. Whether endogenous adenosine is a trigger for this reflex remains controversial. Muscle interstitial adenosine concentration can be determined by microdialysis. However, there are indications that local muscle cell damage by the microdialysis probe confounds these measurements in exercising muscle. T...

Intravascular fibrin deposition was induced in rabbits by endotoxin, the infusion of fibrin monomer (FM), and by the infusion of thrombin and EACA. A previously developed radioisotope technique was used to measure the fibrin deposits in various organs. Dipyridamole treatment of rabbits caused significant inhibition of fibrin deposition in all three experimental models. The drug also inhibited p...

Two main hypotheses concerning the mechanisms responsible for coronary collateral growth suggest the involvement of chemical or mechanical factors. Since we recently demonstrated that the development of the coronary collateral circulation is not closely related to the extent or duration of myocardial ischemia, we hypothesized that chronic repeated vasodilation and increased myocardial blood flo...

To the Editor: A new medication, Aggrenox, a formulation of aspirin and extended-release dipyridamole, is being actively marketed to physicians for the treatment of patients with transient ischemic attacks and ischemic stroke. Physicians involved in pharmacological stress testing should be aware that patients taking this medicine may also be referred for pharmacological stress perfusion testing...

The effects of intracellular ribavirin on morphology and redistribution of phosphatidylserine (PS) in human erythrocytes were examined. Erythrocytes were incubated with 1 mM ribavirin in the presence/absence of dipyridamole, an inhibitor of es-type nucleoside transporter. Intracellular ribavirin was accumulated in erythrocytes with the concentration of 1361 muM, which corresponds to the blood l...

Regional myocardial blood flow before and after intravenous dipyridamole (0.56 mg/kg) was measured during cardiac catheterization in 11 patients using the 133Xe washout technique. Significant increases in heart rate (75 +/- 4 vs 87 +/- 6, p less than 0.004) and decreases in systolic blood pressure (144 +/- 8 vs 131 +/- 7, p less than 0.02) were observed with dipyridamole infusion. However, doub...

Transesophageal echocardiography allows the evaluation of proximal coronary artery anatomy and coronary blood flow velocity (CBFV). To assess the potential of transesophageal echocardiography in evaluating CBFV and its variations induced by coronary-active drugs, we studied 15 patients by high-quality pulsed wave Doppler recordings of CBFV. In these patients, transesophageal Doppler evaluation ...